package com.astrob.util;

import java.math.BigDecimal;

/**
 * Created by colin on 2017/7/25.
 */

//System.out.println(ArithUtil.add(0.01, 0.05));
//System.out.println(ArithUtil.sub(1.0, 0.42));
//System.out.println(ArithUtil.mul(4.015, 100));
//System.out.println(ArithUtil.div(123.3, 100));

public class ArithUtil {
    private static final int DEF_DIV_SCALE=10;

    private ArithUtil(){}

    public static double add(double d1,double d2){
        BigDecimal b1=new BigDecimal(Double.toString(d1));
        BigDecimal b2=new BigDecimal(Double.toString(d2));
        return b1.add(b2).doubleValue();

    }

    public static double sub(double d1,double d2){
        BigDecimal b1=new BigDecimal(Double.toString(d1));
        BigDecimal b2=new BigDecimal(Double.toString(d2));
        return b1.subtract(b2).doubleValue();

    }

    public static double mul(double d1,double d2){
        BigDecimal b1=new BigDecimal(Double.toString(d1));
        BigDecimal b2=new BigDecimal(Double.toString(d2));
        return b1.multiply(b2).doubleValue();

    }

    public static double div(double d1,double d2){

        return div(d1,d2,DEF_DIV_SCALE);

    }

    public static double div(double d1,double d2,int scale){
        if(scale<0){
            throw new IllegalArgumentException("The scale must be a positive integer or zero");
        }
        BigDecimal b1=new BigDecimal(Double.toString(d1));
        BigDecimal b2=new BigDecimal(Double.toString(d2));
        return b1.divide(b2,scale,BigDecimal.ROUND_HALF_UP).doubleValue();
    }

}
